This invention relates to an acoustical device for an internal combustion engine and more particularly to an improved device for generating the desired sounds from either or both of the engine induction system and the engine exhaust system.
Various devices have been proposed for use in conjunction with internal combustion engines so as to provide the desired sound in either or both of the induction system and the exhaust system. Generally, the desired sound has been achieved by providing acoustical devices that will tune or minimize the frequencies which are not desired so as to retain the desired frequencies. The problem with these systems is that they require multiple devices to tune out multiple frequencies other than the frequency or frequencies desired. Various types of silencing devices have been employed for attempting to cancel out or reduce the objectionable or undesirable frequencies and these include such things as side branch, resonators and Helmholtz resonators.
It is, therefore, a principal object to this invention to provide an improved acoustical device for an engine that will be capable of rather than tuning out undesired frequencies, amplifying the desired frequencies so as to simply the system.
It is a further object to this invention to provide such an acoustical device for either or both of the engine induction and exhaust systems.
This invention is adapted to be embodied in an internal combustion engine comprised of an engine body forming at least one combustion chamber. An induction system is provided having an atmospheric communication opening for introducing at least an air charge to the combustion chamber. An exhaust system is also provided for discharging exhaust gasses from the combustion chamber through an atmospheric communicating opening. An acoustical device for amplifying sounds of a predetermined frequency is provided in at least one of the induction and exhaust systems and has an opening facing the atmospheric communicating opening of the system.